1. Field of the Invention
The present invention relates to a graft grasping device. More specifically, the present invention relates to a graft grasping device capable of grasping by negative pressure a graft having an open anastomosing port during coronary artery bypass grafting.
2. Description of the Related Art
In order to treat ischemic heart diseases such as angina pectoris and myocardial infarct, percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) are carried out. Of these, PTCA, which is not highly invasive, has been very popular in recent years. However, CABG is suitably selected for patients having a lesion in the left main coronary artery, patients having a lesion in the 3 major ramuses, and patients who suffer from restenosis very often after PTCA. Currently, CABG is carried out on about 15,000 patients a year in Japan and about 10 times more patients in Europe and the US.
CABG, in which part of an autograft such as a great saphenous vein is used as a bypass graft under general anesthesia, is carried out by a surgeon. More specifically, one end of the bypass graft is sutured with the aorta and the other end is sutured with a region after the stenosis portion of the coronary artery. After CABG, the blood bypasses the stenosis portion and runs from the aorta to the myocardium through the newly transplanted bypass graft.
When the bypass graft is anastomosed with the aorta or the coronary artery, it must be grasped while its anastomosing port is open. Therefore, a pair of tweezers or the like has been conventionally used. However, grasping with tweezers or the like may damage the intima of the bypass graft. This is because the ends of the tweezers contact the intima of the graft. Also, most of the tweezers or the like are made from a hard material such as a metal and are made uneven to prevent slipping. Thus, there is a fear that the intima of the graft may be further damaged. When the intima of the bypass graft is damaged, the adhesion of a thrombus to the damaged part or intimal thickening may occur, thereby increasing the possibility of restenosis occurring. When restenosis occurs, a surgical operation is needed again, thereby increasing a burden on a patient. Also, in the case where only part of the anastomosing port is grasped with the tweezers, the anastomosing port of the bypass graft cannot be opened wide.
In view of the above, a graft grasping device in which a bypass graft is suction-grasped by a grasping portion composed of a circular hollow tube in the form of a ring having a plurality of suction ports in the inner portion of the ring has been proposed for use in place of the conventional tweezers (see Japanese laid-open publication No. JP 2002-360593 A).
However, since the graft grasping device of said invention has a grasping portion that is a ring formed from a circular hollow tube, when the bypass graft is suction-grasped, the contact area between the grasping portion and the graft is small, causing a fear that the graft may be separated from the grasping portion by a small force during a surgical operation. That is, when sufficiently high ease of operation is to be obtained while the graft is grasped, the contact area between the grasping portion and the graft must be large. Also, to insert a graft having almost the same diameter as the inner diameter of the grasping portion, the grasping portion must be opened wide. To open the grasping portion wide, the grasping portion must be made from a material having sufficiently high flexibility. However, when such a soft flexible material is used for the grasping portion, the grasping portion may be crushed by a suction force, causing a fear that the bypass graft may not be suction-grasped. The graft grasping device of JP 2002-360593 A is not provided with means for preventing the crushing of the grasping portion. Further, the anastomosing port of a bypass graft is cut obliquely in most cases to ensure a flow of blood. To suction-grasp this bypass graft, it must be grasped at a position away from the end of the anastomosing port. In this case, there is another fear that the anastomosing port may not be opened wide.
As a result of earnest investigations made by the inventors to solve the problems associated with the conventional techniques, the present invention has been completed.
An object of the present invention is to open an anatomosing port of a bypass graft to an anatomosing region without causing damage to an intima during a bypass operation.